Protesters blockaded the Athens Stock Market on Tuesday, on the eve of a general strike, as the leader of Greece's largest labor union warned the government's fiscal austerity measures could lead to an "eruption" in unemployment.

About 100 protesters from a union backed by the Greek Communist Party staged the blockade, but stock market officials said the exchange was still running through online trading. Police did not intervene to end the protest.

The incident was the latest sign of growing labor opposition to the Socialist government's plans for tougher spending cuts to cope with a debt crisis that has affected confidence in the euro as a common currency.

On Wednesday, the country's main unions will stage a 24-hour general strike that is set to halt public services and ground flights, adding to Europe's airline travel disruption caused by walkouts elsewhere.

Yiannis Panagopoulos, leader of Greece's largest labor union, the GSEE, warned that cuts that lead to a loss of income for wage-earners would push the country deeper into recession.

"There is already a surge in unemployment, and I fear there will be an eruption in levels of (joblessness in 2010) that will really cause social shock waves," Panagopoulos told the AP in an interview.

Greek unemployment hit a five-year high of 10.6 percent in November 2009, up from 9.8 percent in October.

"The Greek people are well aware that the fiscal situation of the country is in terrible shape ... But the measures are not fair. We demand a fair distribution of the burden so that wage-earners and pensioners do not pay the price for a crisis they did not create," Panagopoulos said.

"What people must realize is that Greece is being used as a pingpong ball in an international game of speculators and geopolitical interests who are targeting the euro ... But people's needs are much more important that those of the markets."

The European Union says Athens must start improving its public finances by a March 16 deadline or be ordered to make more cuts. Officials from the EU and the International Monetary Fund began inspections at the Finance Ministry Tuesday.

Greece's government has imposed hiring and salary freezes along with bonus cuts in the civil service, as well as consumer tax hikes and reductions to government spending.

It has promised to take tougher measures if needed to slash the budget deficit from a projected 12.7 percent last year to 8.7 in 2010. It insists Greece is not seeking financial aid from the European Union but some form of support to borrow money at cheaper rates on the international market — blaming high Greek bond spreads on speculation against the euro.